Comments on: Video chat about the new Kepler planetshttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/
Wed, 21 Nov 2012 15:12:45 +0000hourly1http://wordpress.org/?v=4.0.1By: Matt B.http://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317836
Sun, 18 Mar 2012 00:00:46 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317836I don’t understand how the Kepler-20-f could block almost 1% of the star’s light if it’s only 1% as wide as the star. It would have to be about 10% as wide, making it a gas giant, not rocky planet.
]]>By: David from North Forkhttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317835
Fri, 23 Dec 2011 00:28:13 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317835Are there adjusted units of distance for exoplanet orbits around stars so that 1 in those units is the distance from that star that gives the same amount of light that the Earth gets from the Sun?
]]>By: Alan Gouldhttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317834
Thu, 22 Dec 2011 19:28:24 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317834In the video chat, two issues came up that I can comment on:
1. How are the newly discovered planets confirmed?
Kepler team has been using this terminology: a “confirmation” is accomplished by Earth-based observations of stellar spectrum to detect alternating red-shift/blue-shift caused by gravitational tugging on the star by a planet. This is known as the “radial velocity” (RV) method which is the planet-finding method used by astronomers to find most of the discovered planets to date. When the RV method is not possible (with very small planets or ones too far from the star to have big enough gravitational effect), the Kepler scientists use software to rule out every possible source of a “false positive”. When confidence is high enough in this technique (well over 99% certain), the Kepler team deems it safe to say that the planet discovery is “validated” (as opposed to confirmed).

2. What is BLENDER software?
I don’t know a lot of details, but BLENDER was created to rigorously rule out false positives, by comparing the observed light curve with theoretical light curves of various conditions that might be false positives, the main type being a binary star (two stars orbiting each other) that appears very close to the star under observation, and masquerading as a planet due to similarity in shape of light curve produced.

My bad — I only saw the group of you onscreen and was unaware of other people commenting on the talk as it was happening. I don’t use G+; their hostility towards pseudonymity and inconsistent enforcement of “real names” effectively disadvantages already vulnerable groups (like battered women and political dissidents in tyrannical states). I refuse to participate in such a service.

But that’s beside the point here. I was attempting to point out alternatives and why they might be better, but I guess they’re not better, so never mind.

Messier Tidy Upper@3: If you go to the Kepler Input Catalog search page, you can search for Kepler-20 by its KIC ID of 6850504. The search results tell me it has a surface temperature of 5342 Kelvins, which is consistent with a spectral class of G9 V or K0 V … somewhere right around there.

Thanks for that both of you – very much appreciated.

The search results also give a radius of 70% of our own Sun, which is not consistent with a G9 V spectral class. But I’d be far more confident in the temperature estimation than in the radius. Or maybe there’s something odd about the star… but the temperature is still the leading indicator of these things.

Could that be related to that stars age and evolution given that main-sequence stars gradually become more luminous and perhaps larger over time? Our Sun was once only about two-thirds of its current brightness (eg. Cambrian “faint sun paradox” ) but, I think, was still classed as a G2 V star at that time. Or was it?

]]>By: Vagueofgodalminghttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317830
Wed, 21 Dec 2011 23:18:20 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317830Small point – Kepler-20f isn’t the furthest out (as you must realise from the graphic showing large-small-large-small-large). It’s d that’s the outermost one: the order is b, e, c, f, d. I think the reason is that the lettering follows the order of discovery as confirmed planets, and there was a period when b, c, d were confirmed but not yet e and f.

Surprised none of you had heard of BLENDER – the Kepler team have published quite a bit on it, and several of the previous discoveries (e.g. 10c, 11g) used it.

]]>By: Josh Khttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317829
Wed, 21 Dec 2011 22:16:57 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317829That was wonderful. Phil, I’ve tried to catch some of the other chats on UStream, but have terrible timing and am never able to catch them. I LOVE that you can record these and embed them. I’d still like to watch it live, though, and post some questions.

Good work to Fraser for putting it all together. I Fraser was camera shy or something. Hopefully, Google can fix the feature and allow Hangout to cycle through all the web cams.

]]>By: Fraser Cainhttp://blogs.discovermagazine.com/badastronomy/2011/12/21/video-chat-about-the-new-kepler-planets/#comment-317828
Wed, 21 Dec 2011 19:41:57 +0000http://blogs.discovermagazine.com/badastronomy/?p=42182#comment-317828A Hangout on Air is limited to 8 participants, but an unlimited number of people can view it. A regular Hangout can have 10 people, but nobody can watch it.

So the Hangout we did yesterday was “On Air”, which allowed hundreds of people to watch the live stream as we did it. People were commenting and chatting as the video was happening.

Although other tools like Buzzumi are cool, I think we’re going to keep using the Google option because it integrates so well with the other services we use, like Youtube.

I don’t understand the “plebes” comment. We’ve had non-stop participation in our Google+ Hangouts. Now that we have Hangouts on Air capability, everyone can at least watch and comment.

I’ve recently, however, become aware of a new service called Buzzumi that allows exactly the sort of thing that #12 has in mind. They have four different “chat” formats, one of which, “Interview” is described as “You and up to one hundred guests. Everyone can chat via text; only you and guests you select have video and audio.” I do not know if there is any option to record the chat for later.

I’m not a Buzzumi employee nor have I even used the service, so all this should be taken with a grain of salt. But there are a lot of options out there besides G+ Hangouts that don’t require participation in the Google Empire, and can enable some of us plebs to participate as well.